1. Field of the Invention
The present invention relates to an apparatus for producing semiconductor and other devices, and more particularly to an apparatus for performing film deposition, etching, etc. on semiconductors and so on (e.g., semiconductors, magnetic substances, conductors, dielectrics and other materials).
2. Description of the Related Art
(1) An apparatus for producing semiconductor and other devices, shown in FIG. 10, has been known heretofore.
Semiconductor substrates are cleaned in a cleaning apparatus 1 and then stocked in a carrier 215 (FIG. 11) disposed in a transfer means MTV.
Upon a predetermined number of substrates being stocked in the carrier 215, the carrier 215 including those substrates is carried by the transfer means MTV into any of loading/unloading chambers 8a, 8b, 8c, 8d of the apparatus for producing semiconductor and other devices.
The semiconductor substrates having entered any of the loading/unloading chambers 8a, 8b, 8c, 8d are loaded into standby rooms 9a, 9b by a robot arm (not shown) in a robot room 5, and then transferred through a transfer room 6 to any of dry treatment chambers 7a, 7b, 7c, 7d, 7e where dry treatment (such as film deposition and etching) is performed on the substrates.
After the dry treatment, the semiconductor substrates are transferred to the standby rooms 9a, 9b through the transfer room 6, and then carried back to the loading/unloading chambers 8a, 8b, 8c, 8d by the robot arm in the robot room 5.
In the above apparatus, however, the substrates held in the transfer means MTV are exposed to the atmosphere in a clean room after being cleaned. Particularly, because the carrier 215 usually accommodates about 20 pieces of substrates, a period of about 1 hour is required in some cases from the time at which the first substrate is stocked in the carrier 215 to the time at which the last twentieth substrate is stocked therein. During such a period of time, the substrates held in the transfer means MTV continue exposed to the atmosphere in the clean room.
Exposure to the atmosphere causes impurities to adhere to the substrate surfaces even in the clean room. If film deposition is performed on the substrates with impurities kept adhered to their surfaces, the quality of the deposited films may deteriorate and the yield of the produced devices may reduce.
(2) Meanwhile, there is also known another apparatus for producing semiconductor and other devices, shown in FIG. 12 (see Japanese Unexamined Patent Publication No. 4-14222).
This apparatus comprises a loading/unloading chamber 101, dry treatment chambers 109, 110, a wet treatment chamber 115, and a transfer room 116. The transfer room 116 serves to transfer substrates between the dry treatment chambers 109, 110 and the wet treatment chamber 115.
In this apparatus for producing semiconductor and other devices, because wet treatment can be performed prior to dry treatment, the problem stated in connection with the above related art (1) is solved to some extent. More specifically, a substrate placed in the loading/unloading chamber 101 is transferred from the loading/unloading chamber 101 to the wet treatment chamber 115 through the transfer room 116. In the wet treatment chamber 115, wet treatment is performed on the substrate to remove impurities having adhered to it in the clean room. Thus, some amount of impurities can be removed by performing the dry treatment after the wet treatment. Accordingly, the apparatus of this related art (2) can provide better film quality than obtainable with the above related art (1).
An improvement in film quality resulted with the related art (2) is, however, not so satisfactory as expected. The reason is as follows. In the apparatus of the related art (2), an object to be treated, i.e., a substrate, is loaded from the loading/unloading chamber 101 into the wet treatment chamber 115 after having passed the transfer room 116. Stated otherwise, because the substrate is transferred through the transfer room 116 while impurities are kept adhered to the substrate, the transfer room 116 is inevitably contaminated.
In the apparatus of the related art (2), though not shown, the substrate is cleaned by some means before being carried into the loading/unloading chamber 101.
Further, the above-cited Japanese Unexamined Patent Publication No. 4-14222 does not disclose details of the wet treatment performed in the wet treatment chamber 115, and therefore what kinds of chemicals are used to perform the wet treatment is not clear.